The concept of crimping electrical terminals to permanently terminate electrical wires is widely accepted in industry for both power and signal uses. In general, a connector or terminal is made of conductive metals such as copper or alloys thereof to include a forward portion shaped to be engaged by a post or tab or equivalent structure and a rearward portion having a preformed shape adapted to receive a conductor inserted or laid therein with the rearward portion thereafter being inelastically deformed to effect an intimate and gas type metallurgical bonding of the metal of the terminal to the metal of the conductive wire. In this process, a wide variety of crimp shapes and geometries have evolved including a family of crimps which initially are tubular to receive wires inserted therein and a family of crimps which are U-shaped to receive wires laid therein with terminal ears folded thereover. In most cases, the terminal portions are deformed through the elastic region and into an inelastic deformation leading to the extrusion of the surfaces of the terminal and the wires to effect a long lived and permanent electrical joint. This is accomplished by dies of different shapes for differently designed crimps, such dies being in turn driven by a variety of mechanisms which may be incorporated into hand tools or through the use of mechanized sources of force including electric motor driven presses, air presses or in the high force region, hydraulic presses. In all cases, the requirements of the crimp involve essentially a displacement of dies requiring a certain force versus the travel of the dies, a certain work in terms of inch pounds, and a certain frictional load over and above the work actually required for deformation of the terminal and wire. These various requirements are intrinsic to the terminal and wire of use and must be met, and in fact exceeded by the mechanism including the dies employed to effect crimps.
In all the foregoing, the constant problem has been one which relates to the fact that to effect a good crimp, exceedingly high forces are required in the tail end of total displacement, forces in excess of 500 pounds to 6,000 pounds being commonly required for a wide variety of crimps of terminals to wires in the range of 10 or 12 up to 26 AWG. As a general rule, the initial forces required are quite low, on the order of 50 to 100 or 150 pounds with the high forces coming only in the last ten percent of the total displacement required. The general answer to this requirement has been to provide sources of force and work far greater than actually required by the terminal, making for both inefficiency and added cost of crimping tools. When employed in factories for high volume usage with ready sources of inexpensive power, these inefficiencies become almost irrelevant to a highly leveraged amortization due to volume. In what is known as premise wiring wherein relatively few terminations are done per day per site, the concept of overpowering the requirements of the crimp and the relatively high costs of tooling associated therewith, becomes unattractive and unacceptable from a design standpoint. As an example, the so-called bench press crimping tools driven by motors ranging from a tenth to one horse power, employ clutch mechanisms and drive linkages capable of hundreds, if not thousands of inch pounds of work are employed to crimp terminals which range between 20 and 120 inch pounds of work actually required. In the factory where thousands of crimps per day may be expected for a crimping press, this kind of overdesign is readily acceptable, at least economically. In premise wiring and in the field where a given crimping tool may do 10 to 100 crimps per day, the economics of this prior approach are unacceptable. So too with respect to the use of energy where the cost of power per crimp in a factory is relatively insignificant, compared with the cost of energy on premise which may have to be at a given time, specially introduced to a given premise location for the few hours needed for the few crimps for that particular job site.